A three-dimensional optical photonic crystal

We report on the successful fabrication of a working three-dimensional (3-D) crystal operating at optical wavelength lambda. The minimum feature size of the 3-D structure is 180 nm. The 3-D crystal is free from defects over the entire 6-inch silicon wafer and has an absolute photonic bandgap (PBG) centered at lambda similar to 1.6 mu m. Our data pro,ides the first conclusive evidence for the existence of a complete 3-D PEG in optical lambda. This development will pave the way to tinier, cheaper, more effective waveguides, optical switches and lasers.